Passengers at Union Station after their Amtrak train from Los Angeles became stuck in snow drifts on Tuesday, Jan. 7, 2014, in Chicago. / Andrew Nelles, AP

by Larry Copeland, USA TODAY

by Larry Copeland, USA TODAY

More than 500 passengers who spent the night aboard three Amtrak trains stranded in snow in Illinois were finally headed by bus Tuesday morning to Chicago, rail line officials said. All of the passengers were expected to arrive in Chicago by early afternoon.

The trains - the Southwest Chief from Los Angeles, the Illinois Zephyr from Quincy and the California Zephyr from the San Francisco Bay area - were halted starting around 3:30 p.m. CT Monday between Princeton and Mendota, about 80 miles from Chicago, said Amtrak spokesman Marc Magliari. He said that drifting snow and ice made the tracks impassable. No injuries were reported.

Some passengers told news outlets by cellphone that conditions on their train deteriorated and that they went long periods without food. "The conditions is cold; we're wearing coats. And my husband is a diabetic. He hasn't had any food all day," Laurette Mosley told ABC News. "The bathrooms are flooded. The sinks are full with water and the toilets are flooded."

However, another passenger, Sarah Johnson, 19, told The Chicago Tribune and WGN-TV that passengers on her train were fed a meal of beef stew and mashed potatoes with a dinner roll and coffee or water around 6:45 p.m. She said the staff was pleasant and trying to make people comfortable, although no one was able to tell them what was happening from about 10:30 p.m. until about 6 a.m. "The staff of the train have really been trying to make everyone as happy and comfortable as possible," she said.

Magliari said two of the trains, the Southwest Chief and the California Zephyr, were full-service trains with café cars. The Illinois Zephyr, which had about 60 passengers aboard, "had only one food service option," a snack bar, he said.

Magliari said, "There were always working toilets on all the trains." He said some toilets might have malfunctioned, but "We were never without toilets."

About 300 passengers spent the night on two of the trains near Mendota. The 217 passengers on the third train, the California Zephyr, spent the night at a rail yard in Galesburg. "We were unable to charter buses to take the passengers to Chicago (from Galesburg)," Magliari said.

He said the other two trains were stuck in a remote area of Bureau County where "the tracks go through sort of a trench" that made it difficult to remove passengers at the time.

"So we felt it was safer to shelter in place with light and heat and toilet systems than transfer passengers through the trench in the snow at minus-5 temperatures," Magliari said. He said that emergency workers and medical personnel were standing by through the night if they had been needed.

Passenger Bryan Plummer told ABC News that people on his train were given dinner but no snacks during the 15 hours they were stranded. "I inquired about breakfast service and they stated that at this time there was none planned. When the sheriff's officer that was on board here, when he left around 3 a.m. this morning. He stated that the Red Cross was involved and was trying to get us some meals."

Amtrak canceled nearly two dozen trains in Illinois on Tuesday because of the cold and lingering snow from a weekend storm that dumped more than a foot of snow in some areas of Illinois.